Generally, an electric vehicle is driven by an electric motor supplied with energy from a battery and driven.
The electric vehicle may, for example, include a plug-in hybrid electric vehicle (PHEV), a battery electric vehicle (BEV), a fuel cell electric vehicle (FCEV), and the like.
A high-voltage battery pack (hereinafter, referred to as a battery pack) is installed in such an electric vehicle, and the electric vehicle is driven using a driving motor as a power source. The driving motor operates by receiving power from the battery pack.
The battery pack has a large volume and heavy weight, and thus a vehicle needs an enough installation space for installation of the battery pack in the vehicle.
Such a battery pack is provided in a lower portion of a center floor panel that is disposed between side sills of an under body of the vehicle.
For example, the battery pack is mounted with the side sill to the lower portion of the center floor panel through various mounting units such as a bracket and the like.
However, an under body for an electric vehicle according to a conventional art requires an additional mounting unit to mount a battery case to the lower portion of the center floor panel together with the side sill through a battery cross member, and accordingly, the number of parts and the number of assembling processes for assembling the mounting unit are increased, thereby causing an increase of the weight of the vehicle body.
Thus, the under body for the electric vehicle needs a space for parts such as the mounting unit for installation of the battery pack and a space for forming a gap for suppressing generation of noise between the battery case and the center floor panel, and accordingly, alignment of the battery panel cannot be freely designed and an increase of capacity of the battery pack is limited.
Further, in the under body for the electric vehicle according to the conventional art, the battery pack is simply supported by the lower portion of the center floor panel through the side sill together with the battery cross member, and thus when a side collision occurs, safety and durability with respect to an impact load cannot be sufficiently assured, thereby causing a damage to the battery pack.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.